Stuck on logo screen after rooting, how can I move past this?

[AC Question]

Stuck on logo screen after rooting

So... I decided to attempt - yea you read it right - attempt to root my phone - a complete noob and amateur at that (hell idfk wtf is rom or stock or flash - enlighten me later thx)

And from stalking and going through some threads, (they sounded very helpful) about how I got stuck on the logo screen;

Recovery booting....
Recovery is not seandroid enforcing (wtf this even means???)
Set Warranty Bit : recovery

not to mention,
i did the volume down + home key + power key thingy
and got into the downloading screen, which; this time displays,

ODIN MODE
PRODUCT NAME : SM-G900F
CURRENT BINARY: CUSTOM
SYSTEM STATUS: Official
REACTIVATION LOCK(KK): OFF
KNOX WARRANTY VOID: 0x1 (4)
(in grey) QUALCOMM SECUREBOOT: ENABLE (CSB)
AP SWREV S1, T1, A1, P1
(in blue) SECURE DOWNLOAD : ENABLE
(in red) UDC START

trust me, im only posting this coz im at my wit's end ;__;
that's about all i could get from my phone now
i need answers on how to get it back before i tried rooting it